rockchip: rk3399: add support for ddrfreq suspend/resume

This patch sets the frequency configuration of the next DRAM DFS index
to the configuration of the current index. This does not perform a
frequency transition. It just configures registers so the training on
resume for both indices will be correct.

Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
diff --git a/plat/rockchip/rk3399/drivers/dram/dfs.h b/plat/rockchip/rk3399/drivers/dram/dfs.h
index ab7276f..3204ae7 100644
--- a/plat/rockchip/rk3399/drivers/dram/dfs.h
+++ b/plat/rockchip/rk3399/drivers/dram/dfs.h
@@ -66,4 +66,7 @@
 uint32_t ddr_get_rate(void);
 uint32_t dram_set_odt_pd(uint32_t arg0, uint32_t arg1, uint32_t arg2);
 void dram_dfs_init(void);
+void ddr_prepare_for_sys_suspend(void);
+void ddr_prepare_for_sys_resume(void);
+
 #endif